a couple of things before you go ottwith pin hole sharpness:
1. the 'beauty of pinhole images lies inthe fact that they are not perfectly sharp, don't ruin that.
2.there are two different 'optimal pinhole diameters; one one for maxresolution and one for max contrast(sharpness)
I see some etched pinholes in my near future! But I will compare to laser and EXPERTLY filed holes.
Why,some may ask, do I wanna make sharp looking pinholes. At this time I make everything that is used producing my final image, EXCEPT the lense. I make all my emulsions and everything else that goes into, or is used producing, my final piece of work, EXCEPT the lens. Call me a narcisistc egomaniac if you so choose. But my goal is to make Everything that goes into my final images. I don't think that I could ever produce quality lenses. Since my final images are Pt/Pd/Au/Pigment based color separation work, I usualy strive for only one image per year. That is working everyday.:alien: High production ain't my bag.
Thanks. I think I scanned it at high res and did some mesaurements and calculations. ~f/226 is what I came up with.
Originally Posted by Mainecoonmaniac
I've got to go back to a point Ralph just made. Maybe I got lucky crafting such a sharp pinhole -- I did a lot of research at the time and was pretty meticulous. But I remember being initially disappointed with the super sharp images I was getting. In some cases (like what I posted) it worked well, but I was after something softer and not so perfect, like many of the great pinhole images I had seen in books and online.
Given all of this, you could try making some pinholes. You have more than enough patience. A needle, some emery paper and patience is all that it takes.
Originally Posted by wildbillbugman
Originally Posted by wildbillbugman
I was wondering what kind of camera you use and what your focal length is? I recently got me some "perfect pinholes" normally used for elektron microscopes. If I have the right size for you, I'm willing to mail you one so you can experiment with it before buying an "expensive" pinhole? In return you can send me a nice print made with the pinhole.
Send me a PM with your address if interested.
"Have fun and catch that light beam!"
Bert from Holland
my blog: http://thetoadmen.blogspot.nl
Linkedin pinhole group: http://tinyurl.com/pinholegroup
I have sent to you a private message with all info. I am getting a bit excited about this. I hope that you are not repulsed by insects. Macro "Portraits" of bugs, magnified to the extream , is my specialty.
I think if you are planning to use this for macro, the calculations for your optimal pinhole might be different. I seem to remember reading that the pinhole can be smaller for macro work. Haven't tried it myself but I think there are people here who will know. You might want to check this before deciding on a size.
Edit: http://www.apug.org/forums/forum62/1...y-pinhole.html has a link.
If you are going acid etched (or laser) you can probably get a bunch of them made for nearly the price of one if you are going to an etching or laser cutting place.
a pin hole can easily produce 7 lp/mm,and consequently is as 'sharp' as it gets or needs to be. your eyes cannot resolve more than that anyway, but i agree with the comment about contrast vsresolution'sharpness is more about contrast than resolution!
Hi Wild Bill
Mike Walker here I make the Harman Titan pinhole cameras, acid etched holes are superior to laser holes, and if done the right way they very very round, I am going to upset some here, put round does not matter that much, it is more the sharpness of the inside edge of the hole.
I can back this up, as Schneider once had a play with this, and by taking 3 scalpel blades interlocking they and blacking with candle smoke made what they said, was as sharp a pinhole as it was possible to make.
Hope this helps.